For this use the fan feature, not the rotating method. The rotating feature is for engineers developing fans themselves. For what you need, a fan is simply a pressure rise, but is dependent on the backpressure (this is why we have fan curves)
Basically your fan could be a 40mm round extrude that is 10mm long, don't worry about the fan blade detail at all. When setting up the simulation, you would select the two side of the fan extrude that represent the entrance face and the exit face, that's it.
You may need to set up a custom fan curve though if it's not loaded in SolidWorks. This is easy to do, just Google "plot digitizer" to download software that will allow you to select points off the pdf spec sheet of the fan, and it will output the points into excel. Then you can cut and paste these excel values into SolidWorks.
Thanks for the reply Brendan. I am clear know.
I'd recommend looking through the tutorials for flow. There is an example of each.